Nursing Elites

1. What property of matter refers to the amount of space occupied by an object and is measured in cubic units?

• A. Mass
• B. Density
• C. Weight
• D. Volume

Correct answer: d

Rationale: Volume is the property that refers to the amount of space occupied by an object and is measured in cubic units such as cubic meters or cubic centimeters.

2. The term "bioaccumulate" refers to...

• A. The natural decomposition of organic materials.
• B. The buildup of a substance in living organisms.
• C. The contamination of seawater with chemical pollutants.
• D. The physical entanglement of animals with plastic debris.

Correct answer: B

Rationale: The passage describes microplastics entering food chains and accumulating in organisms, aligning with bioaccumulation.

3. Melanin, the pigment responsible for skin color, is produced by

• A. Keratinocytes (These cells produce keratin)
• B. Melanocytes
• C. Sebocytes (These cells produce sebum)
• D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: The correct answer is B: Melanocytes. Melanin, the pigment responsible for skin color, is produced by melanocytes, which are specialized cells located in the skin's epidermis. Melanocytes transfer melanin to keratinocytes, the predominant cell type in the epidermis, where it provides protection against UV radiation. Sebocytes produce sebum, an oily substance that helps moisturize the skin and hair. Langerhans cells are a type of immune cell that play a role in the skin's immune response. Therefore, the correct answer is B as melanocytes are specifically responsible for producing melanin.

4. Vaccines work by stimulating the immune system to develop:

• A. A physical barrier against pathogens
• B. An inflammatory response
• C. Immunological memory to a specific pathogen
• D. Phagocytes to engulf pathogens

Correct answer: C

Rationale: The correct answer is C: 'Immunological memory to a specific pathogen.' Vaccines work by introducing a harmless form of a pathogen or a piece of it to stimulate the immune system. This exposure triggers the production of antibodies and memory cells specific to that pathogen. These memory cells 'remember' the pathogen, allowing the immune system to respond more effectively and rapidly if exposed to the actual pathogen in the future. Options A, B, and D are incorrect because vaccines do not create a physical barrier, induce a general inflammatory response, or directly cause phagocytes to engulf pathogens; instead, vaccines enhance the immune system's ability to recognize and combat specific pathogens.

5. Which of the following statements is true regarding a supersaturated solution?

• A. It is unstable and tends to crystallize
• B. It contains less solute than it could dissolve
• C. It has a lower concentration than a saturated solution
• D. It is rarely encountered in everyday solutions

Correct answer: a

Rationale: Supersaturated solutions are unstable and tend to crystallize if disturbed. The other choices do not accurately describe supersaturated solutions.

6. A ball is thrown horizontally off a cliff with a speed of 10 m/s. What is the horizontal distance the ball travels before hitting the ground?

• A. 10 m
• B. 20m
• C. 30m
• D. Cannot be determined without knowing the height of the cliff

Correct answer: C

Rationale: When a ball is thrown horizontally, its horizontal velocity remains constant throughout its motion. The time taken to hit the ground is determined by the vertical motion, which is independent of the horizontal velocity. Therefore, the horizontal distance traveled by the ball is determined by the horizontal velocity and the time taken to hit the ground. In this case, the horizontal distance is calculated as distance = velocity × time = 10 m/s × time. Since the horizontal velocity is 10 m/s and the time taken to hit the ground is determined by the vertical motion, the horizontal distance traveled by the ball is 10 m/s × time. Without knowing the height of the cliff, we can still determine the horizontal distance traveled by the ball, which is 10 m/s × time.

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